The 5 Series BMW ABS Control Unit ECU is a clever and central part of the anti-lock braking system and crucial to its performance. A highly advanced computerised part, its function is to control your car's anti-lock braking system, making sure that it works properly.
Sensors on your car wheels monitor the speed at which each wheel is rotating and measure the amount of hydraulic pressure needed. This information is sent back to the ABS Control Unit ECU, which adjusts the brake pressure accordingly, stopping your car wheels from slipping and swerving. This action is repeated constantly and can be felt by the driver as a vibrating motion in the brake pedal. Ultimately, the 5 Series BMW ABS Control Unit ECU ensures your car can stop as quickly as possible without affecting steering and control whilst braking.
If the 5 Series BMW ABS Control Unit ECU has a fault, the ABS alert light will show and the ABS will stop working. This will not affect your ability to apply the brakes, but because the automatic locking system has been disabled it won't stop the wheels from skidding or potentially locking up when you brake.
It's important to check your 5 Series BMW ABS Control Unit ECU as soon as you can if the warning light comes on and if possible don't use your car in rainy conditions when the risk of swerving is high and the braking distance dramatically increased.
If the ABS warning light shows; the brakes are not working; or the brake pedal is really stiff, these are signs that you need to speak to your mechanic and will potentially need to replace your 5 Series BMW ABS Control Unit ECU.